Methods and compositions for treating cannabinoid overdose with a cannabinoid receptor antagonist

ABSTRACT

Disclosed herein are formulations and methods for reversing one or more symptoms of cannabinoid overdose, comprising parenterally administering a CB1 antagonist in an amount sufficient to reverse the cannabinoid overdose symptoms.

This application claims the benefit of priority of U.S. ProvisionalApplication No. 62/862,830, filed Jun. 18, 2019, and U.S. ProvisionalApplication No. 63/037,351, filed Jun. 10, 2020, the disclosures ofwhich are hereby incorporated by reference as if written herein in theirentireties.

Cannabinoid use can produce a syndrome which includes incapacitating,cyclic bouts of nausea and vomiting. The severe nausea and vomiting thatis associated with chronic cannabinoid use is commonly referred to ascannabinoid hyperemesis syndrome (CHS). CHS can be viewed asparadoxical, since a synthetic form of Δ⁹-tetrahydrocannabinol (THC),the principal psychoactive compound present in cannabis, has beenapproved by the U.S. FDA (and regulatory authorities in other countries)for the treatment of chemotherapy-induced nausea and vomiting.

Patients with CHS present to the emergency department (ED) with periodicepisodes of intractable vomiting that are generally unresponsive tostandard antiemetics such as ondansetron and promethazine. Thesepatients can first exhibit severe anxiety and agitation, flushing, andsweating. Patients frequently also experience abdominal pain and severenausea that can be triggered by the sight or smell of food. Thesesymptoms are followed by a second phase consisting of severe, oftenincapacitating nausea and vomiting. During this period, patients oftentake very hot baths to relieve these symptoms; this can result in burnsfrom immersion in scalding water. Resolution of nausea and vomiting mayrequire 24-48 hours, during which time patients receive fluids andelectrolyte replacement. Complete cessation of cannabinoid use duringthis period is critical for symptom relief. However, the interval fromcessation of cannabis use to complete resolution of symptoms (e.g.abdominal pain) may be as along as 1-4 weeks. Patients treated for CHSin the emergency department often require admission to better manageboth the emesis and the ensuing dehydration, electrolyte imbalance, andesophagitis that result from the frequent and severe vomiting.

Authorities consider CHS distinct from acute cannabinoid overdose (alsoknown as acute cannabinoid poisoning or intoxication) because ofdistinct symptoms and temporal patterning.

Although the molecular mechanisms responsible for CHS have not beenprecisely defined, both the links to cannabinoid use as a trigger andthe cessation of use to symptom relief strongly suggest that cannabinoidreceptors, proteins that mediate the pharmacological effects of THC, areresponsible for mediating the primary symptoms (e.g., abdominal pain,cyclic nausea and vomiting episodes) characteristic of CHS. Thewell-described antiemetic effects of THC make the symptoms of CHS,especially the severe and cyclic vomiting, appear paradoxical, becausecannabinoid receptors (specifically the CB-1 subtype) within braincenters known to control vomiting mediate these antiemetic effects ofTHC. However, long term, frequent cannabinoid consumption that isclaimed to be a requisite for the emergence of CHS, may also sensitizeCB-1 receptors located on the nerves within the gastrointestinal tractresulting in the characteristic stomach pain, cyclic nausea and vomitingof CHS.

CHS does not respond to standard antiemetics, and there are nomedications with demonstrated efficacy in treating the symptoms (i.e.,abdominal pain, nausea, and vomiting) of CHS which trigger emergencydepartment visits and subsequent hospital admissions. Patients generallyreceive intravenous fluids and electrolytes, and are instructed to stopusing cannabinoids. Thus, there is a clear need for rapid acting,specific medications to reverse the symptoms of CHS.

The identification of cannabinoid receptors more than 25 years ago ledto the synthesis of many compounds which bind to these receptors withhigh affinity and specificity. Moreover, compounds have been identifiedthat, on binding to cannabinoid receptors, and specifically the CB-1receptor subtype, function as antagonists. That is, unlike THC and othercannabinoids which mimic the effects of THC (act as agonists), thesecompounds do not activate CB-1 receptor mediated signaling but can blockor reverse the pharmacological effects of cannabinoids mediated viathese receptors. Multiple, structurally diverse high affinity CB-1antagonists have been described in the peer reviewed literature.Consistent with this body of literature, there are two clinical studiesdemonstrating that oral administration of CB-1 antagonists (surinabant,drinabant) can prevent (that is, block) some of the pharmacologicaleffects of smoked or inhaled THC in normal volunteers. However, the slowonset of these compounds following oral administration (maximum plasmaconcentrations achieved in 2-3 h) and the core symptoms of CHS(abdominal pain, nausea, and vomiting) make oral dosing impractical. Inorder to be useful and effective in treating CHS, a CB-1 antagonist mustbe able to produce a clinically meaningful reduction in the coresymptoms of CHS and be administered by a route that insures rapid onsetand full delivery of the desired dose.

Accordingly, described herein are compositions and methods foralleviating the symptoms of cannabinoid hyperemesis syndrome (CHS) usingthe CB-1 antagonist drinabant (AVE 1625) or a salt or polymorph thereofvia parenteral administration.

DETAILED DESCRIPTION

Disclosed herein are compositions and methods to treat, reverse, orreduce cannabinoid hyperemesis syndrome (CHS) or one or more symptomsthereof comprising parenterally administering a CB1 antagonist in anamount sufficient to reverse the symptom(s).

In certain embodiments, the CB-1 antagonist is drinabant, or a salt orpolymorph thereof.

In certain embodiments, the plasma concentration of drinabant sufficientto reverse the cannabinoid overdose symptom(s) ranges from about 200 toabout 730 ng/ml.

In certain embodiments, such as, for example, in an emergency setting,the parenteral route of administration is chosen from among intravenous(IV), intramuscular (IM), and subcutaneous (SC).

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof. sufficient to reverse the CHS symptom(s) is between about 1 mgand about 150 mg per dose, between about 1 mg and about 100 mg per dose,between about 1 mg and about 60 mg per dose, between about 15 mg andabout 60 mg per dose, between about 30 mg and about 60 mg per dose,between about 15 mg and about 30 mg per dose.

In certain embodiments, the parenteral route of administration is IV.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof. sufficient to reverse the CHS symptom(s) is between about 1 mgand about 60 mg per IV dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof. sufficient to reverse the CHS symptom(s) is between about 15 mgand about 60 mg per IV dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof. sufficient to reverse the CHS symptom(s) is between about 15 mgand about 30 mg per IV dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof. sufficient to reverse the CHS symptom(s) is between about 30 mgand about 60 mg per IV dose.

In certain embodiments, the IV dose is delivered by IV injection.

In certain embodiments, the IV dose is delivered in a liquid volume ofbetween about 1 and about 20 mL.

In certain embodiments, the IV dose is delivered in a liquid volume ofbetween about 1 and about 20 mL, distributed across two or more pushes.

In certain embodiments, the IV dose is delivered by IV infusion (IVN).

In certain embodiments, the IVN dose is delivered in a liquid volume ofabout 50 mL to about 500 mL, about 50 mL to about 125 mL, or about 250mL to about 500 mL. In certain embodiments, the IVN dose is delivered ina liquid volume of about 50 mL, about 100 mL, about 125 mL, about 250mL, or about 500 mL.

In certain embodiments, the IVN dose is delivered over a period of about30 min to about 120 min. In certain embodiments, the IVN dose isdelivered over a period of about 30 min, about 60 min, about 90 min, orabout 120 min.

In certain embodiments, the IVN dose is delivered in a liquid volume ofbetween about 125 to about 500 mL.

In certain embodiments, the IVN dose is delivered over a period of about1 hour to about 2 hours.

In certain embodiments, the IVN dose is delivered at a rate of about 0.5mL/min to about 2 mL/min.

In certain embodiments, the parenteral route of administration is IM orSC.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to reverse the cannabinoid overdose symptom(s) isbetween about 5 mg and about 100 mg per IM dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to treat, reverse, or reduce the CHS or one or moresymptoms thereof is between about 5 mg and about 60 mg per IM dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to treat, reverse, or reduce the CHS or one or moresymptoms thereof is between about 15 mg and about 60 mg per IM dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to treat, reverse, or reduce the CHS or one or moresymptoms thereof is between about 15 mg and about 30 mg per IM dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to treat, reverse, or reduce the CHS or one or moresymptoms thereof is between about 30 mg and about 60 mg per IM dose.

In certain embodiments, the IM dose is delivered in a liquid volume ofup to about 2.5 ml. In certain embodiments, the IM dose is delivered ina liquid volume of about 1 mL to about 2.5 ml.

In certain embodiments, the IM dose is delivered by injection into adeltoid or gluteal muscle.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to treat, reverse, or reduce the CHS or one or moresymptoms thereof is between about 1 mg and about 100 mg per SC dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to treat, reverse, or reduce the CHS or one or moresymptoms thereof is between about 5 mg and about 100 mg per SC dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to treat, reverse, or reduce the CHS or one or moresymptoms thereof is between about 5 mg and about 60 mg per IM dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to treat, reverse, or reduce the CHS or one or moresymptoms thereof is between about 15 mg and about 60 mg per IM dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to treat, reverse, or reduce the CHS or one or moresymptoms thereof is between about 15 mg and about 30 mg per IM dose.

In certain embodiments, the amount of drinabant, or a salt or polymorphthereof sufficient to treat, reverse, or reduce the CHS or one or moresymptoms thereof is between about 30 mg and about 60 mg per IM dose.

In certain embodiments, the SC dose is delivered in a liquid volume ofup to about 1.5 ml. In certain embodiments, the SC dose is delivered ina liquid volume of about 1 mL to about 1.5 ml.

In certain embodiments, the IV, IVN, IM, or SC dose or injection isdelivered as a solution, suspension or emulsion.

In certain embodiments, the IV, IVN, IM, or SC dose or injectioncontains at least one agent that acts as a non-ionic solubilizer and/oremulsifying agent.

In certain embodiments, the agent that acts as a non-ionic solubilizerand/or emulsifying agent comprises polyoxyl 15 hydroxystearate or amixture of polyglycol mono- and di-esters of 12-hydroxystearic acid.

In certain embodiments, the agent that acts as a non-ionic solubilizerand/or emulsifying agent which comprises polyoxyl 15 hydroxystearate isKolliphor® HS 15 (CAS No. 70142-34-6) or Solutol HS 15 (polyglycol mono-and di-esters of 12-hydroxystearic acid with about 30% polyethyleneglycol).

In certain embodiments, the symptom(s) of CHS are chosen from abdominalpain, nausea, and vomiting.

In certain embodiments, the onset of reversal of symptom(s) of CHS areapparent within 5-30 minutes following IV injection of drinabant, or asalt or polymorph thereof.

In certain embodiments, the onset of reversal of symptom(s) ofcannabinoid overdose are apparent within 30-60 minutes following IVNinjection of drinabant, or a salt or polymorph thereof.

In certain embodiments, the onset of reversal of symptom(s) of CHS areapparent within about 15 min to about 45 min following IM or SCadministration of drinabant, or a salt or polymorph thereof.

In certain embodiments, if no response is observed within about 30minutes to about two hours of a first administration of drinabant, andthe presence of cannabinoids is confirmed or strongly suspected, asecond dose may be administered.

Definitions

As used herein, reversal, attenuation or reduction of CHS symptom(s) isapparent when, in the judgment of a trained healthcare giver (e.g.,physician, nurse practitioner, nurse, paramedic, or emergency medicaltechnician), the symptom(s) have abated to a noticeable degree, which isinterpreted as a clinically meaningful reduction in the frequency orseverity of symptoms. Such a caregiver may use any appropriate measureto quantify the reversal of symptom(s), e.g., the number of bouts ofvomiting and/or nausea, number of patient complaints of abdominal painor discomfort etc. Similarly, visual analog scales (VAS) can be used toquantify a reduction in severity (e.g. rate the abdominal pain on ascale from 1 to 10 with 1 as little or no discomfort to 10 as “worstpain ever”)— such scales can also be used by the patient to assess theseverity of nausea and vomiting bouts. The “apparent” reversal orattenuation of symptom(s) includes, but need not extend to, completecessation of symptoms.

As used herein, the term “cannabinoid” is synonymous with “cannabinoidreceptor agonist” and refers to a compound or compounds which binds toand activates a cannabinoid receptor. This would include cannabinoidsand structurally related compounds found in cannabis, but also termincludes synthetic compounds that are structurally unrelated to THC andother chemicals found in cannabis.

As used herein, the term “cannabinoid receptor antagonist” refers to acompound which binds to and blocks or dampens the normal biologicalfunction of the receptor and its signaling, especially in the presenceof an agonist or partial agonist. The term includes cannabinoid receptorantagonists that are selective or nonselective for the CB1 receptorsubtype, i.e., a “CB1 antagonist.”

As used herein, the term “intramuscular (IM)” means administered into amuscle. Suitable muscles, if of sufficient mass, include the deltoid(upper arm), the thigh (esp. the anterolateral aspect of the thigh;particularly useful if via an autoinjector), the gluteus maximus(typically only adults and children >3 years old), and hip. The IMinjection may be via a classical syringe or an autoinjector device.

As used herein, the term “intravenous (IV)” means delivered as a liquidinto a vein of a patient. Intravenous administration can be by injection(in a relatively small volume and at relatively high concentration) byinjection via a syringe or into a previously-inserted IV catheter, or byintravenous infusion (“IVN,” in a relatively larger and more dilutevolume). IV administration, particularly injection, can be done in oneor more pushes.

The terms “non-ionic solubilizer” and/or “emulsifying agent” and/or“solubilizing agent” are generally interchangeable as used herein, andinclude agents that result in formation of a micellar solution or a truesolution of the agent being solubilized and a typically immisciblepartner (for example, drinabant, which has a high log P, and water,which has a negative log P). Solubilizing agents include cationic andnonionic surfactants, and in certain circumstances may also act asabsorption or permeation enhancers. One example of a solubilizing agentis Kolliphor HS 15/Solutol HS 15 (e.g., CAS No. 70142-34-6 or61909-81-7, polyoxyl 15 hydroxystearate, polyglycol mono- and di-estersof 12-hydroxystearic acid with about 30% polyethylene glycol).

As used herein, the term “parenteral” means administered by means otherthan oral, nasal (i.e., bypassing mucous membranes) or rectal intake,particularly intravenously or by injection elsewhere, e.g.,intramuscular or subcutaneous injection.

As used herein, the term “push” in the context of an intravenous (IV)push is the rapid administration of a small volume of medication into apatient's vein, typically via a previously inserted IV catheter.Multiple pushes make be used to comprise a single IV dose.

As used herein, the term “subcutaneous” means “under the skin,” i.e.,administered into the subcutis, the layer of skin directly below thedermis and epidermis (collectively referred to as the cutis), abovemuscle.

As used herein, a “symptom” of CHS is a physical or mental feature thatis regarded as is a departure from normal function or feeling. Typicalfeatures of CHS are well known to those skilled in the art and aredescribed in the literature, generally including severe, cyclic nauseaand vomiting that is not relieved by standard anti-nausea agents (e.g.ondansetron), and abdominal pain (that can be generalized or more local(e.g., epigastric or periumbilical).

As used herein, the term “in need of treatment” and the term “in needthereof” when referring to treatment are used interchangeably and referto a judgment made by a health caregiver (e.g. physician, nurse, nursepractitioner, that a patient will benefit from treatment.

As used herein, the term “subject” is intended to be synonymous with“patient,” and refers to any mammal (preferably human) who exhibitssymptoms associated with CHS described herein and falls into a ‘highrisk’ category (individuals with a history of long term, frequentcannabis: 68% of patients consumed cannabis for >2 years before symptomsoccurred; 95% used cannabis more than once a week.

As used herein, to “treat,” “treating,” “treatment,” and the like inreference to CHS means, to a clinically meaningful degree, to reduce,attenuate, reverse, or eliminate its cause or progression, or theseverity and/or frequency of one or more of its symptoms, or otherwiseameliorate CHS in a subject.

Cannabinoid Receptor Antagonists

Cannabinoid receptor antagonists are known in the art, and may beselective or nonselective for CB1. Potency and selectivity for the CB1receptor are generally desirable because cannabinoids producing CHS areCB1 agonists. Rimonabant(5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide)was the first-developed potent and selective CB1 antagonist, onceapproved as an anti-obesity agent in Europe. Many CB1 antagonistsreported so far are 1,5-diarylpyrazole analogs, often featuring apara-substituted phenyl ring at the pyrazole 5-position and a2,4-dichloro-substituted phenyl ring at the pyrazole 1-position. Otheranalogues in this class include surinabant and AM-251. Additionalanalogues featuring core replacements include 3,4-diarylpyrazolines,4,5-diarylimidazoles, and 1,5-diarylpyrrole-3-carboxamides, fusedbicyclic derivatives of diarylpyrazole, diaryl-imidazole, diaryl-purines(e.g. otenabant), six-membered ring pyrazole bioisosteres such as2,3-diarylpyridines and 2,3-diarylpyrimidines, and methylsulfonamideazetidine derivatives. This last class includes drinabant((±)-N-{1-[bis(4-chlorophenyl)methyl]-3-azetidinyl}-N-(3,5-difluorophenyl)methanesulfonamide),also potent and selective for CB1. Rimonabant, once approved as an oralformulation for the treatment of obesity and smoking cessation inEurope, was withdrawn from the European market, and the development ofdrinabant halted, due to rimonabant's concerning side effects includingpsychiatric effects such as depression and mood alterations.

However, these side effects are of far less concern when the intendeduse, instead of daily and long-term, will be limited to indicationswhere the administration is acute and transient, such as reversal thesymptoms of CHS. Accordingly, any potent and selective CB1 antagonistwith adequate target tissue penetration would be expected to work in themethods and formulations disclosed herein.

Plasma concentrations of CB1 antagonists useful in reversing thesymptoms of CHS will vary based on several factors, including theidentity of the antagonist. For example, plasma concentrations ofdrinanbant useful in reversing the symptoms of cannabinoid overdoserange from about 200 ng/mL to about 730 ng/mL. Additionally, it isunderstood by those skilled in the art that the because drinabant hasbeen characterized as a competitive CB1 receptor antagonist, effective(therapeutic) plasma concentrations are dependent upon the dose and typeof cannabinoid responsible, and the frequency and duration thecannabinoid has been taken. Both the onset and degree of symptom reliefmay vary, and some symptoms (e.g. abdominal pain) may be more sensitiveto reversal than others (e.g., nausea). It is anticipated that onset ofsymptom relief should be apparent within about 5 min to about 30 minfollowing intravenous administration and about 15 min to about 45 minfollowing intramuscular or subcutaneous administration, respectively.

In order to achieve these plasma concentrations, intravenous doses ofdrinabant of between about 1 mg and about 150 mg, about 1 mg and about100 mg, or between about 1 mg and about 60 mg, or between about 15 mgand about 60 mg, or between about 30 mg and about 60 mg, or betweenabout 1 mg and about 30 mg, or between about 15 mg and about 30 mg, orbetween about 50 mg and about 100 mg may be administered. Intravenousdoses can be injected in volumes of about 1 to about 20 mL (lowervolumes are preferred in certain circumstances).

Alternatively, in order to achieve these plasma concentrations,intramuscular or subcutaneous doses of drinabant of between about 1 mgand about 150 mg, about 5 mg and about 100 mg, or between about 5 mg andabout 60 mg, or between about 15 mg and about 60 mg, or between about 30mg and about 60 mg, or between about 15 mg and about 30 mg, or betweenabout 50 mg and about 100 mg, or between about 5 mg and about 50 mg, orbetween about 5 mg and about 30 mg. Intramuscular or subcutaneous dosescan be injected in a volume of up to about 2.5 mL for IM and about 1.5mL for SC. Intramuscular injections are typically into a deltoid orgluteal muscle.

In certain embodiments, the doses above take into account thepossibility that fatty tissue may act as a sink for a lipophiliccannabinoid antagonist, which may diffuse in and out of the fatty tissueover time. In any event, if no response is observed with ˜30-45 minutesof parenteral administration, and the presence of cannabinoids isconfirmed or strongly suspected, a second dose may be administered.

Examples

Table 1 below discloses several examples of compositions which can beformulated for parenteral administration (i.e., as liquid preparations)comprising an amount of drinabant or a salt or polymorph thereofeffective to reverse CHS or one or more symptoms thereof in a subject.

TABLE 1 Ex. Mode Dose, mg Vol, mL 1 IV 1 1 2 IV 1 2 3 IV 1 3 4 IV 1 5 5IV 1 10 6 IV 5 1 7 IV 5 2 8 IV 5 3 9 IV 5 5 10 IV 5 10 11 IV 15 1 12 IV15 2 13 IV 15 3 14 IV 15 5 15 IV 15 10 16 IV 30 1 17 IV 30 2 18 IV 30 319 IV 30 5 20 IV 30 10 21 IV 45 1 22 IV 45 2 23 IV 45 3 24 IV 45 5 25 IV45 10 26 IV 60 1 27 IV 60 2 28 IV 60 3 29 IV 60 5 30 IV 60 10 31 IV 1001 32 IV 100 2 33 IV 100 3 34 IV 100 5 35 IV 100 10 36 IM 5 1 37 IM 5 1.538 IM 5 2 39 IM 5 2.5 40 IM 15 1 41 IM 15 1.5 42 IM 15 2 43 IM 15 2.5 44IM 30 1 45 IM 30 1.5 46 IM 30 2 47 IM 30 2.5 48 IM 45 1 49 IM 45 1.5 50IM 45 2 51 IM 45 2.5 52 IM 60 1 53 IM 60 1.5 54 IM 60 2 55 IM 60 2.5 56IM 100 1 57 IM 100 1.5 58 IM 100 2 59 IM 100 2.5 60 SC 5 0.5 61 SC 5 162 SC 5 1.5 63 SC 15 0.5 64 SC 15 1 65 SC 15 1.5 66 SC 30 0.5 67 SC 30 168 SC 30 1.5 69 SC 45 0.5 70 SC 45 1 71 SC 45 1.5 72 SC 60 0.5 73 SC 601 74 SC 60 1.5 75 SC 100 0.5 76 SC 100 1 77 SC 100 1.5

Table 2 below discloses several examples of compositions which can beformulated for parenteral administration as an IV infusion, comprisingan amount of drinabant or a salt or polymorph thereof effective toreverse the cannabinoid overdose or one or more symptoms thereof in asubject. The drinabant may be delivered, e.g., over the given timeinterval (period, in minutes) below.

TABLE 2 Ex. Mode Dose, mg Vol., mL Per., min 78 IVN 5 50 30 79 IVN 5 10030 80 IVN 5 125 30 81 IVN 15 50 30 82 IVN 15 100 30 83 IVN 15 125 30 84IVN 30 125 60 85 IVN 30 125 90 86 IVN 30 125 120 87 IVN 30 250 60 88 IVN30 250 90 89 IVN 30 250 120 90 IVN 45 250 60 91 IVN 45 250 90 92 IVN 45250 120 93 IVN 45 500 60 94 IVN 45 500 90 95 IVN 45 500 120 96 IVN 60250 60 97 IVN 60 250 90 98 IVN 60 250 120 99 IVN 60 500 60 100 IVN 60500 90 101 IVN 60 500 120

Assays and Protocols

Clinical Trial Protocol for CHS

The efficacy of cannabinoid antagonists e.g. drinabant may be tested ina field trial, e.g. of patients presenting at a health care facilitysuch as an emergency department (ED).

Inclusion and enrollment. In the following proposed double-blind,placebo-controlled field trial protocol, a subject would qualify forinclusion if, in the ED physician's opinion, the individual fulfillsboth the specified symptom set and profile of a CHS patient, andreceives a diagnosis of CHS. Such symptoms and profile features of CHSinclude, e.g., the following:

1. chronic, heavy use of cannabinoids such as smoked cannabis;

2. cyclic/recurrent episodes of severe nausea and intractable vomiting;and, optionally:

3. abdominal pain;

4. prior experience of temporary relief of symptoms by taking a hot bathor shower; and

5. prior experience of resolution of symptoms when cannabis use isstopped.

Additional symptoms and patient profile characteristics mat be deemedrelevant; see, e.g., Sorensen C J et al., “Cannabinoid HyperemesisSyndrome: Diagnosis, Pathophysiology, and Treatment—a SystematicReview,” J Med Toxicol 2017, 13(1): 71-87; Sullivan S., “Cannabinoidhyperemesis,” Can J Gastroenterol 2010, 24(5): 284-85. If in thephysician's judgment inclusion criteria are met, and in the physician'sjudgment no criteria present a safety risk sufficient to exclude thesubject, and the subject gives informed consent, the subject may enterthe trial.

Baseline Assessments. Prior to intervention, baseline assessments aretaken of the following symptoms in each patient and recorded:

frequency of bouts of nausea;

severity of nausea (using a visual analog scale (VAS));

frequency of vomiting;

severity of vomiting (using a VAS);

frequency of abdominal pain; and

severity of abdominal pain (using a VAS).

Optionally, other symptoms may be followed (e.g. esophagitis, which issecondary to vomiting and more difficult to quantify), but thesecomprise the “core” symptoms of CHS as presently understood. See, e.g.,Simonetto D A et al., “Cannabinoid hyperemesis: a case series of 98patients,” Mayo Clin Proc. 2012 February; 87(2):114-9. Assessments maybe self-reported or observed by the clinician and these should bedistinguished.

Visual analog scales are known in the art. For example, a visual analogscale for nausea is disclosed in Meek R et al., “Use of the visualanalog scale to rate and monitor severity of nausea in the emergencydepartment,” Acad Emerg Med 2009, 16(12):1304-1310. In this study, a“standard 100 mm” VAS (from no nausea to nausea as bad as it possiblycould be) was used alongside self-reporting of nausea in emergencydepartment patients reporting nausea on a Likert scale as “none, mild,moderate, or severe” at enrollment, 30 minutes, and 60 minutes, andpatients were also “asked to describe any change in nausea severity fromthe previous rating (a lot less, a little less, the same, a little more,or a lot more).” The study found “very good correlation between verbaldescriptors of nausea and VAS ratings,” and the “minimum clinicallysignificant difference (MCSD) in VAS rating of nausea severity” wasdetermined to be 22 mm. Other studies of nausea and vomiting reportingand VAS use somewhat different VAS scales (such as 0 to 5 or 0 to 10)and/or assess frequency of vomiting/dry retching (none, sometimes, mostof the time, all the time; none, once or twice, three times or more inthe last given unit of time; fraction of the last hour or other unit oftime), and/or assess the persistence of the nausea (constant orintermittent). It is within the skill of the clinician to select thecriteria most informative for efficacy readout in the trial.

These assessments will be repeated following interventions as discussedbelow.

Randomization and Intervention. Subjects are randomized according to thefollowing protocol to receive, in addition to symptomatic treatment(fluids and/or electrolytes), either:

-   -   IV drinabant administered at one or more doses sufficient to        achieve a plasma concentration in the range of from about 200        ng/mL to about 730 ng/mL, in about 1 to about 20 mL (lower        preferred)—for example, between about 1 and about 60 mg (by way        of more specific example, between about 15 and about 60 mg, or        between about 30 and about 60 mg);    -   or placebo, in a similar volume.        Alternatively or in addition—either concurrently or after        reversal is achieved via the IV route—IM- and/or SC-dosed groups        may be employed or similar trials constructed, with dosing as        set forth in paragraphs above in a volume of about up to about        2.5 mL for IM doses and/or in a volume of about up to about 1.5        mL for SC doses.

The intervention is administered (placebo or active) and the subject isthen observed for, e.g., 2 hours. During this time, the physicianre-assesses symptoms as disclosed above; this may be done multipletimes. If after dosing, in the opinion of the physician, there is nodiminution in symptoms within 2 hours, the subject is administered adose of second dose of this treatment (either placebo or active) via thesame route as the first dose, and is observed for another 2 hours.Again, during this time, the physician re-assesses symptoms as disclosedabove; this may be done multiple times. If symptoms have not improvedwithin this further 2 hours, the subject receives a third administrationconsisting of the other treatment, via the same route as the first twodoses. For example, if the subject receives 2 doses of active via the IVroute and there is no improvement, the subject would receive placebo viathe IV route, and visa-versa. In this way, patients would receive nomore than 2 doses of active. At least one final assessment is done asdisclosed above.

Results. An intervention with an active pharmaceutical ingredient, e.g.,drinabant, is deemed effective if it reduces compared to placebo thefrequency and/or severity of i) nausea, ii) bouts of vomiting, and/oriii) abdominal pain in a clinically meaningful fashion compared toplacebo. In CHS, a response rate twice that of placebo would beconsidered a clinically meaningful improvement to those skilled in theart. For example, if 30% of placebo-treated patients show a clinicallymeaningful improvement in one or more of the trial measures describedabove, drinabant administration would result in an improvement in atleast 60% the patients. This would result in a ‘number needed to treat’(NNT), a statistical measure commonly used to assess drug efficacy, of3.3 (1/0.6-0.3), a value that would encourage use of this medication byED physicians. It is expected that drinabant, administered at a dosesufficient to achieve a plasma concentration in the range of from about200 ng/mL to about 730 ng/mL, will reduce compared to placebo thefrequency and/or severity of i) nausea, ii) bouts of vomiting, and/oriii) abdominal pain in a clinically meaningful fashion.

Solubility Protocol

Drinabant may be added to a fixed volume of aqueous solution with andwithout various amounts of water soluble carriers such as Solutol HS 15in screw capped bottles. Samples are shaken (alternatively, stirred) fora length of time (e.g., 48 hours) at room temperature, pH optionallyadjusted, and any suspensions filtered through, e.g., a Whatman filterpaper no 1. Filtered solutions are then analyzed for drinabantconcentration using an appropriate method such as UV/visiblespectrophotometry at an appropriate wavelength (nm) or by HPLC. It isexpected that at low concentrations of solubilizing agent (e.g., 1, 5,or 10%), improvement in solubility will increase linearly, but that athigher concentrations this trend may deviate.

Although the present invention has been described with reference tospecific details of certain embodiments thereof in the above examples,it will be understood that modifications and variations are encompassedwithin the spirit and scope of the invention.

What is claimed is:
 1. A composition formulated for parenteraladministration comprising an amount of drinabant or a salt or polymorphthereof effective to reverse cannabinoid overdose or one or moresymptoms thereof in a subject.
 2. The composition as recited in claim 1,further comprising at least one agent that acts as a non-ionicsolubilizer and/or emulsifying agent.
 3. A method of treating,reversing, or reducing cannabinoid overdose or one or more symptomsthereof in a subject, comprising parenterally administering to thesubject an amount of drinabant or a salt or polymorph thereof, effectiveto treat, reverse, or reduce cannabinoid overdose or one or moresymptoms thereof.
 4. The method as recited in claim 3, wherein theplasma concentrations achieved by parenteral administration of drinabantor a salt or polymorph thereof sufficient to treat, reverse, or reducecannabinoid overdose or one or more symptoms thereof is between about200 ng/mL to about 730 ng/mL.
 5. The method as recited in claim 4,wherein the parenteral route of administration is chosen from amongintravenous (IV), intramuscular (IM), and subcutaneous (SC).
 6. Themethod as recited in claim 5, wherein the parenteral route ofadministration is IV.
 7. The method as recited in claim 6, wherein theIV dose is delivered by IV injection.
 8. The method as recited in claim7, wherein the IV dose is delivered in a liquid volume of between about1 mL and about 20 mL.
 9. The method of claim 6, wherein the IV dose isdelivered by IV infusion.
 10. The method as recited in claim 9, whereinthe IV infusion is delivered in a liquid volume of between about 50 mLto about 500 mL.
 11. The method as recited in claim 9, wherein the IVinfusion is delivered over a period of about 30 minutes to about 2hours.
 12. The method as recited in claim 9, wherein the IV infusion isdelivered at a rate of about 0.5 mL/minute to about 2 mL/minute.
 13. Themethod as recited in claim 9, wherein the onset of reversal ofsymptom(s) of cannabinoid overdose is apparent within 30 minutes toabout 60 minutes.
 14. The method as recited in claim 5, wherein theparenteral route of administration is IM or SC.
 15. The method asrecited in claim 14, wherein the amount of drinabant, or a salt orpolymorph thereof sufficient to reverse the cannabinoid overdosesymptom(s) is between about 5 mg and about 100 mg per IM dose.
 16. Themethod as recited in claim 14, wherein the SC dose is delivered in aliquid volume of between about 1 mL and about 1.5 mL.
 17. The method asrecited in claim 3, wherein if no response is observed within about 30minutes to about 2 hours of a first administration of drinabant, and thepresence of cannabinoids is confirmed or strongly suspected, a seconddose may be administered.